> There is also a 'forced shutdown' API, but for whatever reason in testing for me it has always been slower than a graceful shutdown. I have no idea what it do

> There is also a 'forced shutdown' API, but for whatever reason in testing for me it has always been slower than a graceful shutdown. I have no idea what it does internally I have sort of reverse engineered what the two options ("shutdown", "force shutdown") in AWS do. A regular shutdown causes the hypervisor to issue the equivalent of "init 0" to the VM, over whatever communication channel is used between dom0 and domU. Semantically this is treated as a request. If the VM is completely catatonic, the domU kernel won't be able to process the request and will just fail. A forced shutdown causes the hypervisor to issue a similar request, but also puts the VM on a watchlist. If the domU kernel has not terminated in a given time window, probably 10 or 20 minutes[ß], the hypervisor will nuke the VM. ß: I'm not entirely sure about the time window, 10 and 20 minutes are what I have witnessed most often. I have on one occasion seen a VM take 90 minutes get nuked. And of course it was a legacy snowflake system that we couldn't just respawn on demand. That was fun.